In knee OA, which muscular tightness may be observed?

• A. Tight iliotibial band without other findings
• B. Lengthened quadriceps
• C. Hypermobile patella
• D. Short or stiff hamstrings and gastrocnemius

Answer: (D)

In knee OA, surrounding muscles often become tight as a protective response to pain and reduced activity, with the posterior muscles most commonly affected. Short or stiff hamstrings limit knee flexion because they cross the knee joint on the back side, pulling and restricting bending. The gastrocnemius crosses both the knee and ankle, so when it’s tight it resists knee extension and contributes to a stiff, slower gait. Together, tight hamstrings and a stiff gastrocnemius create the characteristic pattern of generalized knee stiffness seen in OA and help explain the ROM limitations patients experience. The other patterns don’t fit as well: iliotibial band tightness tends to cause lateral knee pain and isn’t a defining OA feature; a lengthened quadriceps would not reflect the common OA tendency toward protective muscle tightness and weakness; hypermobile patella implies laxity rather than the typical OA-related tightness.